Open AccessA STUDY ON MECHANISM OF DOPPING IN a-Si:H
Author(s) -
戴国才,
张瑞勤,
关大任,
蔡政亭
Publication year - 1989
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.38.829
Subject(s) - cndo/2 , cluster (spacecraft) , dangling bond , acceptor , materials science , impurity , vacancy defect , boron , hydrogen , molecular orbital , chemical physics , atomic physics , chemistry , crystallography , condensed matter physics , molecule , physics , organic chemistry , computer science , programming language
We have calculated the electronic states and the total energies of a variety of tetrahedrally co-ordinated atomic clusters using the molecular orbital theory CNDO of quantum chemistry. All models in the calculations are based on the cluster Si46 with a single vacancy in the center. We find that for the cluster of Si46H60H4*, in which all dangling bonds are saturated with hydrogen, the donor or acceptor levels in the gap clearly appear when the phosphorus or the boron is introduced substitutionally into the cluster, whereas no clear impurity levels is found for that without hydrogenation. In addition, the increase in total energy resulting from introducing phosphorus (or boron) into the hydrogenated cluster Si46H60H4* is evidently more than that of the cluster without hydrogenation. Our results have been explain d theoretically by the "8-N" rule. The specific role of hydrogen in doping mechanism and some recent experiments are discussed for a-Si:H films.